2-azidocyclohexanone oxime



Unite States Patent Ofitice Patented Apr. 2, 1968 ABSTRACT OF THEDISCLOSURE The new compound, 2-azidocyclohexanone oxime, is ahypotensive agent that can be safely administered to mammals for anextended period of time in an amount sufiicient to lower blood pressure,particularly the diastolic pressure.

This invention relates to the control of blood pressure in mammals andaims to provide a new hypotensive agent.

The prevalence and persistence of hypertension and the serious physicaldisorders that are associated therewith have prompted extensivesearching for chemotherapeutic agents which can be safely administeredover an extended period of time to reduce blood pressure, particularlydiastolic pressure, without producing untoward toxic manifestations ordeleterious side effects. It is highly desirable that a hypotensiveagent exhibit, not only low toxicity and absence of side effects, butalso long duration of activity and smoothness and stability of action sothat the desired reduction of blood pressure may be achieved through theadministration of substantially constant dosage levels of the drug whichwill continue to be etfective over the longest possible intervals. Thesearch for a hypotensive agent having such properties has not beenentirely successful.

We have discovered that the hitherto unknown compound2-azidocyclohexanone oxime is a stable hypotensive agent of very lowtoxicity which exhibits smooth and prolonged activity of a high order.This was surprising because various azides have been included among thecompounds that have been tested for hypotensive activity. For instance,the use of sodium azide is well known but this compound is quite toxic.Different organic azides have also been tested in the past by others whohave reported that they have found them to be ineffective or toofleeting in their action or of insufiicient potency to permit their useas effective hypotensive agents. Hence, the organic azides could nothave been regarded as a promising field within which a superiorhypotensive agent might be found.

Our new compound is particularly noteworthy in the respect that moderateincreases in the size of a non-toxic but effective dose thereof willresult in a proportionate increase in the degree and duration ofhypotensive effect and without an observable increase in toxicmanifestation. The low order of toxicity of our new compound has beenestablished as follows:

Charles River male albino rats, weighing from 200 to 400 grams wereused. The rats were divided into groups of 5 rats each and administeredthe test compound orally at logarithmic increments in a manner intendedto bracket the 50 percent lethal dosage.

The compound was suspended in an aqueous dispersion of 1 percentmethylcellulose Methocel) and administered at a constant volume of 2ml./l00 grams of body weight at all dosage levels.

All rats were fasted for 16 hours prior to administration of thecompound.

All animals were observed for evidence of pharmacotoxic signs andmortality at periodic intervals immediately after administration anddaily thereafter for a total period of 14 days.

Necropsy evalutions were made of all rats which succumbed during theobservation period.

No lesions were observed at necropsy which could be attributed to anefiect produced by the administration of our new compound.

Lesions not related to the compound included congestion, pinpointhemorrhages and pneumonia in 4 of the 11 rats examined.

The acute oral LD data appears in Table 1.

TABLE 1.ACUTE ORAL LD VALUES Z-AZIDOCYCLOHEX- ANONE OXIME IN ALBINO RATSNo. Died/No. Dosed Dosage Level (mg./kg.)

LD and Confidence Limits (mg/kg.)

To test the hypotensive activity of our new compound,

arterial blood pressure in pentobarbitalized (35 mg./kg.) normotensivemongrel dogs of either sex was recorded from the left or rightcannulated femoral artery via a heparinized saline bridge to a StathamP23Db low volume displacement or a Bourdon photoelectric pressuretransducer which in turn was connected to an electronic recorder. Thecontralateral femoral vein was isolated and cannulated for injection ofthe test compound and control substances.

A midline incision was made in the cervical area of the neck and thetrachea was isolated and cannulated to produce a free airway. Bothcarotid arteries were exposed for later occlusions. The right vagusnerve was divided and the peripheral stump passed through tubularplatinum electrodes for later stimulation.

One-half hour was allowed to elapse after dividing the vagus nerve topermit the animal to recover from surgery and the blood pressure tostabilize. Prior to the intravenous administration of2-azidocyclohexanone oxime at least two control responses were obtainedthrough the following procedures:

( 1) Acetylcholine chloride, 2 mcg./kg., intravenously administered. (2)Histamine phosphate, 45 mcg./k g., intravenously administered.

(3) L-Epinephrine bitartrate, 2 mcg./kg., intravenously administered.

(4) Angiotensin II (hypertensin), 1 mcg./k-g., intravenouslyadministered.

(5) Peripheral va-gal stimulation, 5-15 seconds.

(6) Bilateral Cartoid occlusion, l530 seconds.

The control series was administered at least twice prior to injection ofthe test compound. The control series was periodically applied afteradministration of the compound as long as an effect persisted on theblood pressure.

Our new compound is soluble in polyethylene 'glycol (Car-bowax 300), andwas prepared for intravenous administration by dilution in this vehicleto a 25 percent weight/volume concentration. A quantity of our newcompound, solubilized in this manner was further diluted as necessary sothat each dosage level administered would not exceed 2 ml. in volume inany one single administration. Comparable volumes of the solvent withoutcompound were periodically administered for control purposes in eachexperimental trial. Our new compound was individually administered indosages of 1 to 20 mg./kg. to at least two dogs.

A dosage of 1 mg./k g. decreased the mean arterial blood pressure 14percent for minutes. Increase in dosage proportionately increased thedegree and duration of effect in a dose-dependent fashion.

3 Bradycardia (10 to 20 percent) was produced at all TABLE 2.-DEPRESSORPOTENCVY AND DURATION OF ACTION OF Z-AZIDOCYCLOHEXANONE OXIME ON THEMEAN ARTERIAL BLOOD PRESSURE OF ANESTHETIZED NORMOT'ENSIVE MONGREL DOGSMean Arterial Blood Pressure (nun.

Dog Dose, Duration No. mgJkg.

Control Change Percent change (min) Further test results are set forthin the following table:

TABLE 3.BLOOD PRESSURE LOWERPNG EFFECTS Mean Arterial B.P. (mm. Hg.)

Dog N0. Dose Duration (mg. /kg.) Control Fall Percent (min) tall Mean 2218 50 250 o. 5 145 -1s 13 H 32 251 0. 5 133 -8 6 l 14 Mean l3 10 73 Mean28 21 89 Mean l l 33 23 234 In order that our invention will be fullyavailable to those skilled in the art, the preparation of our newcompound is briefly described:

A concentrated aqueous solution of 6.9 g. hydroxylamine hydrochlorideand 5.3 g. anhydrous sodium carbonate was prepared. To it, 13 g. of2-azidocyclohexanone and enough ethanol to make a clear solution wereadded. After stirring for 24 hours at room temperature, the mixture waspoured into excess water. The oil formed was extracted with CI-I CIAfter drying over Na SO the solvent was stripped and the residuedistilled in a short path evaporative distillation apparatus at C. and0.05 mm. Hg to yield approximately 10 g. of a clear oil.

Cal: C, 46.74; H, 6.54; N, 36.34. Found: C, 46.81; H, 6.63; N, 36.64.

2-azidocyclohexanone oxime of this invention may be administeredintravenously, orally, or as an inhalant or spray. For oraladministration, the compound may be associated with a solidpharmaceutical vehicle in the form of a tablet, pill, powder, capsule orother dosage unit form which is suitable for oral administration.Suitable solid vehicles include lactose, cornstarch, microcrystallinecellulose, talc, stearic acid, magnesium stearate, gums and the like.Coated tablets or pills are particularly suitable since the coating willprevent evaporation of the liquid azide from the pharmaceutical carrier.Capsules are also particularly suitable for the same reason. Typicalpharmaceutical capsule ,ggngs such as gelatin may be used.

2-azidocyclohexanone oxime may also be administered in liquid form. Fororal use, liquid emulsions or suspensions containing about 550% axide inwater are suitable. Conventional emulsifying and suspending agents canbe added as stabilizers. These compositions can also contain a smallamount of ethanol which will partially dissolve the azide. Liquid fatsare unsuitable as vehicles since the azides are highly soluble in thesefats and apparently tend to remain dissolved in the chyle.

For intravenous injection or oral use, the azide can be used fullstrength, dissolved in ethanol, polyalkylene oxide or some otherpharmacologically inert vehicle in which the azide is soluble. Forintravenous injection it may also be emulsified in an inert aqueousisotonic solution. Azide concentrations of about 15-75 are suitable. Theazide may also be administered by inhalation or nasal spraying but isnormally not used in this manner because of the difliculty incontrolling dosage. However, in acute.

situations where immediate reduction in blood pressure is necessary,inhalants and sprays are appropriate.

What is claimed is:

1. 2-azidocyclohexanone oxime.

References Cited Fieser, et al.: Adv. Org. Chem. (Reinhold, New York,1962) page 432.

Edwards et al.: Can. J. Chem. 42:712-6 (1964).

JOHN D. RANDOLPH, Primary Examiner.

WALTER A. MODANCE, Examiner.

C. SHURKO, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,376,319 April 2, 1968 Theodor Well et al.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 2, TABLE l,1fth column, last line thereof "0/5" should read 1/5same TABLE, SlXth column, last line thereof, "0/5" should read --5/5same TABLE, seventh column, last line thereof, "0/5" should read 5/5same column 2, line 51, "Cartold" should read carotid Column 4 line 21,"axlde" should read azide Signed and sealed this 19th day of August1969,

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

